In the prior art there is described an inversion polymerization process in this connection see particularly British Pat. No. 748,727. In the British patent the process described comprises forming an initial conversion of monomer to polymer of up to 20% by mass polymerization of monomer in the presence of a suitable catalyst. In this first portion of the polymerization, the monomer is the continuous phase. Thereafter, sufficient water is added to the polymerization system to cause a phase inversion wherein the water becomes the continuous phase forming a dispersion of the unpolymerized monomer in the water. This dispersion is then polymerized to convert essentially all of the remaining monomer to solid polymer. However, the disadvantage of such process is that polymer buildup on the walls of the reactor is excessive and requires cleaning after each batch or run is made.
In U.S. Pat. No. 3,706,722 there is described an inversion polymerization process for producing polymers having improved uniformity and porosity, size and structure. This the patentees accomplished by incorporating a nonionic, monomer-soluble surface active agent in the initial continuous monomer phase. While producing a more porous polymer, the polymer buildup is still a problem and detracts from the use of said process on a commercial basis. This is particularly true when producing polymers and copolymers of vinylchloride where the buildup problem and health hazards are most accute.
Therefore, there is a great need to produce polymers having uniform porosity, size and structure by the inversion polymerization procedure which procedure would substantially eliminate polymer buildup.